Biology And History Assignments

Biology # 8

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The first hypothesis is that fish evolved from vertebrates that moved side to side and slithered in the water on the sea floor. Fish and shark tails are vertical because of this. Aquatic mammals like whales and dolphins move their tails up and down like a fan.

My second and overall hypothesis are Inheritance of Acquired Characteristics and Homologous Structure to explain why these species have evolved differently with things like the tails and fins. Adaption probably also plays a roll, for example how a shark's and dolphin's vertical fin allows for easy access and movement under water while most whales don't have that feature.

They aren't as sleek and fast moving in the water because of it and namely their size. Killer whales are the exception, they resemble dolphins more in that regard, but I believe that since sharks and dolphins are more like predators, the evolution of their bodies is useful for what roles they have in the food chain..

Faster moving creatures have vertical fins while the slower, (maybe) tamer have horizontal fins. I hope it makes sense what I am trying to explain. I understand the chapter and the question, for some reason this assignment is difficult to write and I'm not quite sure why.

For summary, my hypothesis for this can be explained with Acquired Characteristics, Homologous Structure and even Darwin's survival of the fittest because everything evolves for the best traits for a species for its survival.